Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual é a origem do país abreviado como atf?
 ###Tabelas: CREATE TABLE planetary_system (planetary_system_id AUTO_INCREMENT PRIMARY KEY, Companion (in order from star) VARCHAR, Mass VARCHAR, Semimajor axis ( AU ) VARCHAR, Orbital period ( s day ) VARCHAR, Eccentricity VARCHAR, Inclination VARCHAR) CREATE TABLE list_of_oldest_sitting_mps_since_1945 (list_of_oldest_sitting_mps_since_1945_id AUTO_INCREMENT PRIMARY KEY, Born VARCHAR, Became oldest MP VARCHAR, Left House VARCHAR, Age on leaving VARCHAR, Died VARCHAR, Political Party VARCHAR) CREATE TABLE largest_sovereign_wealth_funds (largest_sovereign_wealth_funds_id AUTO_INCREMENT PRIMARY KEY, Country VARCHAR, Abbreviation VARCHAR, Assets US$Billion VARCHAR, Inception VARCHAR, Origin VARCHAR) CREATE TABLE regular_season_attendance (regular_season_attendance_id AUTO_INCREMENT PRIMARY KEY, Year INT, Average VARCHAR, High INT, Sellouts INT, Total for year INT, WNBA game average INT) CREATE TABLE 2007_rankings (2007_rankings_id AUTO_INCREMENT PRIMARY KEY, Team VARCHAR, Country VARCHAR, Value ($M) INT, Debt as %of value VARCHAR, % change on year VARCHAR, Revenue ($M) INT, Operating income($m) INT)  
SELECT Origin FROM largest_sovereign_wealth_funds WHERE Abbreviation = atf